Repeated removal of blood for therapeutic and research purposes is common are of hospitalized patients on clinical trials. To ensure the accuracy of these specimens, the removal of discard blood (5 to 10ml) is standard practice. The reinfusion of this discard blood is not typically done, due to clinical concerns about clot formation. This discard or "wasting" of blood is often a concern for patients and health care providers because of the associated blood loss. The purpose of this study is to determine if discard blood from venous access devices is free from clots and suitable for reinfusion. Blood which is removed for discard prior to obtaining laboratory specimens will be filtered to determine the presence of clots. Half the blood removed as discard from the vascular access device will be filtered immediataely upon removal from the patient to determine the presence of clot. The second half of the discard blood will dwell in a syringe for 5 minutes and then be filterd to determine the presence of clots. The amount of clot presnet in the two samples will be quantified and compared. Discard blood will not be reinfused into patients in this study. A total of fifty (50) vascular access devices will be tested. At this time six of the fifty have been collected, with two instances of clots found in the initial discard specimens. The remaining of sample collections are in process.